1. Field of the Invention
The present invention relates to a stapler, and more particularly to a stapler having a leg-flatting capability and an anvil-guiding device to make an anvil move stably.
2. Description of Related Art
To improve a stapling effect, a conventional stapler has a leg-flatting device to force legs of a staple flat, such that a person and document can be prevented from being injured or broken by the legs of the staple. The leg-flatting device has an anvil element to flatten the legs of the staple, and the anvil element of the conventional stapler may be secured on a supporting base of the conventional stapler. However, there is a gap between the conventional fixed anvil element and the staple, and the gap easily causes low quality of leg-flatting effect.
Another type of conventional leg-flatting device has a slidable anvil element to solve the problem occurred by the fixed anvil element. However, the conventional stapler cannot provide a supporting effect to the slidable anvil element, the slidable anvil element is easily inclined so the leg-flatting effect is also poor.
With reference to FIG. 5, a conventional stapler has a supporting base (90) and a slidable anvil element (92). The supporting base (90) has two guiding channels (902) defined respectively in opposite side faces of the supporting base (90). The anvil element (92) is mounted moveably in supporting base (90) and has a top, two sides and two shoulders. The top is used to clinch legs of a staple and serves as a functional segment (924). The sides are mounted respectively in the guiding channels (902) and have a width larger than that of the top to form the shoulders. The sides and the shoulders serve as a non-functional segment (922). With the guiding channels (902), the anvil element (92) can slide stably during a leg-flatting process of the stapler.
However, the conventional stapler has the following drawbacks.
1. The non-functional segment (922) of the anvil element (92) is not completely mounted in, but partially exposed from the guiding channels (902). The movement of the anvil element (92) is easily influenced. For example, the anvil element (92) may be blocked by an object at a position between the non-functional segment (922) and a corresponding side face of the supporting base (90) to cause unstable movement of the anvil element (92).
2. The anvil element (92) must have sufficient width to be held in the guiding channels (902) in the side faces of the supporting base (90), or the supporting base (90) must have sufficient width to fit with that of the anvil element (92). Therefore, the sizes of the other elements of the stapler are limited accordingly, so the design range for a stapler is also limited.
To overcome the shortcomings, the present invention tends to provide a stapler to mitigate or obviate the aforementioned problems.